Modioli in the Mud

In preparation for netting our lakes, which took place just over a week ago, we dropped the water level in Alder Lake a little, and discovered, as well as lost spods and, sadly, discarded bottles and cans, a large and healthy colony of horse mussels.

modmud The horse mussel (Latin name modiolus modiolus) is a large and long-lived freshwater mussel. The number 25 is key to them as they grow up to 25 cms long and live for up to 25 years. It’s their longevity that makes them inedible, to humans at least, as they become very tough and accumulate a lot of grit and gravel. The first time we found some, we were going to try one as a delicacy, but Chris wisely did some research first and discovered that they basically taste of mud and have the consistency of rubber.

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Horse mussels are widespread in Europe, from the Bay of Biscay to the Arctic, and there are many big beds or reefs of them around the Scottish islands. Almost 400 different types of marine plants and animals have been found associated with these reefs. They thus play an important part in conservation. Five years ago Northern Ireland faced the threat of a fine of £8m from the EU for not adequately protecting its population of horse mussels in Strangford Lough, an Area of Special Scientific Interest and also a Special Area of Conservation.

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We rarely see the horse mussels. They only appear when the lake level drops. They follow the water down, wriggling through the silt. We rescue any stranded ones and pop them back into the lake.

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So our horse mussels are a sign of a healthy ecosystem, and provide the more determined carp with a nice meal, if they can get through the tough shell!